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Old April 8th 14, 10:34 AM posted to,
Geoffrey S. Mendelson Geoffrey S. Mendelson is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 487
Default Hayward design broadband low noise preamp for loops

I have a copy of the book "Practical Wire Antennas" by Heyes (the first
edition). In it is a schematic for a low noise broadband preamplifier
for loops.

This version uses the BSX20 transistor which at the time the book was
written was far more available in the UK than the 2N5179 used by the
original Hayward design.

The book mentions that it was first published in the ARRL Antenna
Handbook, I can not find it in my copy.

These days it is much cheaper and easier to order 2N5179 transistors
from China on eBay (and probably cheaper to order 10 and pick the best)
than it is for me to order a BSX20.

However without the original schematic or construction article, I am
taking it on faith that it will work with no circuit changes, something
I doubt.

A copy of the schematic and accompanying text would be appreciated.
References to where it appeared or links to pages describing it would be
even better.

The original circuit I was looking at contained 1 transistor, 4 diodes,
6 1/4 watt resistors and 4 disk capacitors. The coil could be wound from
hookup wire on a hunk of ferrite rod, which I have many of.

It's fairly "bulletproof", so high voltages from static, lightening
or nearby transmitters (all three here) won't burn it out like an MMIC.

It's a simple design so that I can build it myself. :-)


Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379